Such planetary gears are sufficiently well known to someone skilled in the art. In the interior of a planet gear set, the so-called sun gear turns on a central shaft. Several gears having teeth that engage in the peripheral teeth of this sun gear are provided, in practice usually three to five, which are designated as planet gears due to their obvious arrangement. And as planets, as they rotate they also move in a circular motion about the sun gear, while they simultaneously turn about their own axis. The shafts of the planet gears are fixed on the planet gear carrier, which receives this rotational movement, that is, likewise in the rotational direction about the central axis. As a third element, the ring gear surrounds the entire formation, in that it engages the planet gears with its internal teeth from the outside. Here, the central axis also represents the center of rotation.
The shafts of the planet gears are also designated as planet gear pins and are fixed in the planet gear carrier in various ways.
According to DE 196 11 605 A1, this is realized in that both the planet gear carrier and also the planet gear pins are provided with radially extending holes, in which attachment screws are inserted. After being screwed in, the screw bodies of these attachment screws are both in the planet gear pin and also in the planet gear carrier, so that the planet gear pins are secured against axial displacement. It is obvious that such a position-fixing device of the planet gear pin is very complicated. First, both in the planet gear carrier and also in the planet gear pin, the location holes are to be formed and provided with a corresponding internal thread. Then, both are set relative to each other in the peripheral direction so that the holes align, before finally, the attachment screws can be inserted.
Another such type of attachment follows from the German Utility Model Application DE 74 181 66 U. This is realized in that first a hoop ring is pushed onto the planet gear pin. The ring is connected to the pin by means of a weld. Then, the planet gear pin is secured by means of a retainer ring, which engages in an annular groove of the collar ring and secures this against axial displacement. Here, it can also be recognized that such an attachment of the planet gear pin in the planet gear carrier is very complicated and costly.
Finally, in DE-OS 25 03 518, another type of attachment of the planet gear pin in a planet gear carrier is described. FIG. 2 of this prior publication shows a planet gear carrier comprising two disc-shaped sheet-metal parts welded to each other with a planet gear. The planet gear pin is held in two aligned holes of the two sheet-metal parts of the planet gear carrier. The pin is fixed in that it is stamped at its two end sides. Now, in this respect, it is known to someone skilled in the art that the planet gear pin is subjected to very high loads and therefore must be subjected to a hardening process before being installed in the planet gear gear. Now, in order to carry out stamping of the pins in general at the two opposing end surfaces, they must be subjected to a soft-annealing process. It is obvious that such a process is also very complicated and thus expensive.